Pattern formation using printing is considered as a method of forming an electronic device at low cost. For example, screen printing, gravure printing and ink-jet printing are known as printing methods. However, these printing methods make it difficult to form a fine pattern if the methods are used without modification.
In consideration of this factor, the following method of forming a fine pattern is known. For example, the surface of the substrate for printing is made liquid-repellent. On the liquid-repellent (lyophobic) surface, a lyophilic pattern is formed. In this manner, the surface wettability of the target substrate is made different depending on the region. By applying ink onto the lyophilic pattern through printing, the pattern boundary can be clear. Thus, a fine pattern can be formed.
Ink-jet printing is also known as a printing method to be applied. In ink-jet printing, ink is supplied as droplets. Thus, the ink amount on the lyophilic pattern of the substrate can be adjusted in terms of locations. The size of ink droplets is preferably large in view of productivity and accuracy of landing positions.
In a dip method or a die coating method, ink comes into contact with the surface of the substrate when applied. Thus, ink can be left along the lyophilic pattern. It is possible to realize alignment accuracy and form a fine pattern.